For chemical and biochemical analysis of solid and liquid sample materials, carrier-bound rapid tests have become established in specialized laboratories and in particular also for use out of stationary laboratories. Such carrier-bound rapid tests are based on a specially developed dry chemistry and can be performed easily and in an uncomplicated manner even by a layperson despite the often complex reaction involving sensitive reagents.
Test elements for determining the blood glucose level of diabetics are a familiar example of carrier-bound rapid tests. Diagnostic test elements designed in strips are also referred to as test strips. Known embodiments include for example single-field or multi-field test strips for urinalysis and various indicator papers. In addition to test elements in strip form, other forms of carrier-bound tests also exist, so we speak in more general terms of analytical consumable means. Analytical consumable means can also generally refer to lancet or sample withdrawal elements, not just testing elements.
Such analytical consumable means can be used with a handheld analyzer which analyzes a color change of a test strip, e.g. photometrically by using an optical analysis device. In some systems, analytical consumable means are stored in a rotary drum magazine, such as that described in EP 1 022 565, for example, the disclosure of which is hereby incorporated by reference herein in its entirety. A rotary drum magazine can have several chambers which are, for example, arranged in a ring and may contain the analytical consumable means. Typically, each chamber has an insertion opening and a withdrawal opening on opposite front ends of the rotary drum magazine. These openings are each closed with a sealing film to protect the analytical consumable means from harmful environmental influences such as light, humidity or dust.
With known handheld analyzers such as the “Accu-Chek® Compact Blood Glucose Meter” from Roche Diagnostics GmbH, a check is performed by actuation of a withdrawal device to determine whether an analytical consumable means is still present in a chamber of the rotary drum magazine or whether it has already been withdrawn. The known handheld analyzer has two electric test circuits. A first test circuit is closed by a dog mounted on a push rod of the withdrawal device when this push rod is inserted into a chamber of the rotary drum magazine. If a consumable means is in the chamber, it is ejected by the push rod, and in doing so, a switch is activated by the consumable means, thereby closing a second test circuit. If operation of the withdrawal device results in closing the first test circuit only but not in closing the second test circuit, this means that the respective chamber of the rotary drum magazine is empty.
Other exemplary systems with test element positioning and/or detection means are disclosed in EP 0 779 983 and EP 1 508 807, the disclosures of which are hereby incorporated herein by reference in their entireties.
Handheld analyzers for testing a medically significant component of a sample, such as devices for determining the blood glucose level, are often used by people whose perception or manual dexterity is impaired due to age or illness. It is therefore important for such analyzers to be as easy to handle as possible and that operating errors or malfunctions are ruled out as much as possible.
The object of the invention is to provide a handheld analyzer for testing a medically significant component of a sample and a method for operating such a handheld analyzer that reduces malfunctions or operating errors associated therewith.